Universal joint with reinforced yoke ears and positively locked trunnions

ABSTRACT

A universal joint for vehicle drivetrains and the like that eliminates the spinning of bearing caps relative to yoke years and trunnions and inhibits inadvertent spreading of opposing ears of a yoke away from each other under increasing torsional loads to reduce wear and failure of the joint. Broadly, the disclosed universal joint includes a central body having a plurality of pairs of opposite apertures, first and second yokes that are disposed about the central body over respective ones of the pairs of apertures, and a plurality of trunnions inserted through the yoke ears and into the apertures of the body to pivotally secure the yokes to the body. Each trunnion is non-rotatable relative to its respective yoke and a locking assembly inhibits movement of each opposite pair of trunnions away from each other thereby inhibiting movement of the opposite ears of each respective yoke away from each other.

BACKGROUND 1. Field of the Invention

The present invention generally relates to universal joints forconnecting torque transmitting shafts and, in particular, to a universaljoint for connecting torque transmitting shafts of a drivetrain of amotor vehicle.

2. Relevant Background

A drive axle assembly or drivetrain of an automotive vehicle transmitstorque from an engine and a transmission to drive wheels of the vehicle.The drivetrain changes the direction of the power flow, multipliestorque, and allows different speeds between the two of the drive wheels.Among other components engaged in operative communication with eachother, the drivetrain typically includes one or more universal jointsthat are subject to high torsional loads. A universal joint is acoupling that can transmit rotary power from a first shaft to anadjacent second shaft that is non-collinear with the first shaft.Typically, a universal joint includes a pair of yokes or yoke membersthat are secured to respective drive shafts and that are interconnectedby a cruciform or “spider” for rotation about independent axes (e.g.,perpendicular axes). The spider includes four orthogonal trunnions(pivot pins) with each opposing pair of axially aligned trunnionsmounted in a pair of aligned bores formed in spaced arms of one of theyokes.

A bearing cup or cap is often secured over each trunnion such that eachyoke is supported for pivotal movement relative to its respective pairof the trunnions. Snap rings or the like are typically used to preventinadvertent removal of bearing caps from the trunnions. Variousconventional universal joints having yoke portions are known to thoseskilled in the vehicle driveline art and are widely used in theautomotive industry today.

SUMMARY

Under increasing torsional loads, the bearing caps of existing universaljoints are prone to spinning relative to the trunnions and yoke ears towhich they are attached or secured. Such spinning of the bearing capscan lead to weakening of the yokes, loosening and eventually ejection ofthe snap rings designed to secure the bearing caps to the trunnions, andsometime even failure of the universal joints. Furthermore, when a firstshaft is turned at a significant angle relative to a second shaftthrough existing universal joints and is under extreme torque, forcesare generated that tend to push the first and second opposing ears ofeach yoke away from each other which can lead to weakening and failureof the yokes. Other than the snap rings, existing universal joints aretypically devoid of structure to prevent or at least limit suchinadvertent spreading of opposing ears of a yoke away from each other.

In view of at least the foregoing, disclosed herein is a universal jointfor vehicle drivetrains and the like that eliminates the spinning ofbearing caps relative to yoke years and trunnions and inhibitsinadvertent spreading of opposing ears of a yoke away from each otherunder increasing torsional loads. Broadly, the disclosed universal jointincludes a central body having a plurality of pairs of oppositeapertures, first and second yokes that are disposed about the centralbody over respective ones of the pairs of apertures, and a plurality oftrunnions that are inserted through the yoke ears and into the aperturesof the body to pivotally secure the yokes to the body. Each trunnion isnon-rotatable relative to the yoke that it is pivotally securing to thecentral body to inhibit spinning of the trunnion relative to the yokeand the attendant weakening of the yokes and possible failure of theuniversal joint. In other words, each trunnion may be positively lockedto its respective yoke. For instance, each trunnion having anon-circular head that is configured to be seated into a correspondingnon-circular depression in the yoke. Furthermore, a locking assembly isinserted into one of the pairs of apertures in the central body and isconfigured to inhibit movement of each opposite pair of trunnions awayfrom each other. Inhibiting movement of each opposite pair of trunnionsaway from each other thereby also inhibits movement of the opposite earsof each respective yoke away from each other. The resulting universaljoint can advantageously withstand increasing operational loadssubstantially free of many of the disadvantages of existing universaljoints.

In one aspect, a universal joint for connecting first and second torquetransmitting shafts is disclosed that includes a central body havingfirst and second opposite apertures through which a first reference axisis defined and third and fourth opposite apertures through which asecond reference axis is defined; a first yoke portion that isconfigured to be secured to a first torque transmitting shaft, where thefirst yoke portion includes first and second spaced opposite ears thatare respectively disposed over the first and second opposite apertures;first and second opposite trunnions that are respectively insertedthrough the first and second ears of the first yoke portion and thefirst and second apertures of the central body to secure the first yokeportion to the central body for pivoting about the first reference axis,where the first and second trunnions are non-rotatable relative to thefirst yoke portion; a second yoke portion that is configured to besecured to a second torque transmitting shaft, where the second yokeportion includes first and second spaced opposite ears that arerespectively disposed over the third and fourth opposite apertures; andthird and fourth opposite trunnions that are respectively insertedthrough the first and second ears of the second yoke portion and thethird and fourth apertures of the central body to secure the second yokeportion to the central body for pivoting about the second referenceaxis, where the third and fourth trunnions are non-rotatable relative tothe second yoke portion.

In another aspect disclosed herein, a universal joint for connectingfirst and second torque transmitting shafts includes a central bodyhaving first and second opposite apertures through which a firstreference axis is defined and third and fourth opposite aperturesthrough which a second reference axis is defined; a first yoke portionthat is configured to be secured to a first torque transmitting shaft,where the first yoke portion includes first and second spaced oppositeears that are respectively disposed over the first and second oppositeapertures; first and second opposite trunnions that are respectivelyinserted through the first and second ears of the first yoke portion andthe first and second apertures of the central body to secure the firstyoke portion to the central body for pivoting about the first referenceaxis; a second yoke portion that is configured to be secured to a secondtorque transmitting shaft, where the second yoke portion includes firstand second spaced opposite ears that are respectively disposed over thethird and fourth opposite apertures; third and fourth opposite trunnionsthat are respectively inserted through the first and second ears of thesecond yoke portion and the third and fourth apertures of the centralbody to secure the second yoke portion to the central body for pivotingabout the second reference axis; and a locking assembly disposed withinthe central body and secured to the first, second, third and fourthtrunnions to inhibit movement thereof along the first and secondreference axes, respectively. The depression of each of the first andsecond apertures of the first yoke portion is defined by a lowersurface, and the head of each of the first and second trunnions includesa surface that contacts the lower surface of the respective one of thefirst and second apertures of the first yoke portion to inhibit movementof the first and second ears of the first yoke in first and secondopposite direction along the first reference axis. Furthermore, thedepression of each of the first and second apertures of the second yokeportion is defined by a lower surface, and the head of each of the thirdand fourth trunnions includes a surface that contacts the lower surfaceof the respective one of the first and second apertures of the secondyoke to inhibit movement of the first and second ears of the second yokeportion in first and second opposite direction along the secondreference axis.

In a further aspect disclosed herein, a method of assembling a universaljoint includes positioning first and second spaced ears of a first yokeportion over respective first and second spaced apertures of a centralbody; inserting a first trunnion through the first ear of the first yokeportion and the first aperture of the central body along a firstreference axis until a head of the first trunnion is seated within anon-circular depression of the first ear of the first yoke portion toinhibit relative rotation between the first trunnion and the first yokeportion; inserting a second trunnion through the second ear of the firstyoke portion and the second aperture of the central body along the firstreference axis until a head of the second trunnion is seated within anon-circular depression of the second ear of the first yoke portion toinhibit relative rotation between the second trunnion and the first yokeportion; and inserting a locking apparatus into central body and intocontact with the first and second trunnions to inhibit movement of thefirst and second trunnions along the first reference axis while allowingfor rotation of the first trunnion, second trunnion, and first yokeportion about the first reference axis relative to the locking member.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to thedrawings and by study of the following descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a universal joint according to anembodiment disclosed herein, the universal joint broadly including firstand second yoke portions pivotally attached to a central body.

FIG. 2 is an exploded perspective view of the universal joint of FIG. 1.

FIG. 3 is an elevational view of the universal joint of FIG. 1.

FIG. 4 is a sectional view along the line 4-4 of FIG. 3.

FIG. 5 is a perspective view similar to FIG. 1 but with the first andsecond yoke portions being in a different position relative to eachother.

FIG. 6 is an elevational view of the universal joint of FIG. 5.

FIG. 7 is a sectional view along the line 7-7 of FIG. 6.

FIG. 8 is an elevational view similar to FIG. 6, but with the first andsecond yoke portions being in a different position relative to eachother.

FIG. 9 is a sectional view along the line 9-9 of FIG. 8.

FIG. 10 is an elevational view of the first yoke portion of FIG. 1.

FIG. 11 is a sectional view along the line 11-11 of FIG. 10.

FIG. 12 is an elevational view of the second yoke portion of FIG. 1.

FIG. 13 is a sectional view along the line 13-13 of FIG. 12.

FIG. 14 is a perspective view of a trunnion for pivotally attaching oneof the first and second yoke portions to the central body of FIG. 1.

FIG. 15 is a first elevational view of the trunnion of FIG. 14.

FIG. 16 is a second elevational view of the trunnion of FIG. 14.

FIG. 17 is a plan view of the trunnion of FIG. 14.

FIG. 18 is a perspective view of a locking member for inhibiting axialmovement of the trunnion of FIG. 14 when secured to the central body.

FIG. 19 is an elevational view of the locking member of FIG. 18.

FIG. 20 is a sectional view along the line 20-20 of FIG. 19.

FIG. 21 is a plan view of the locking member of FIG. 18.

FIG. 22 is a perspective view of the central body of FIG. 1.

FIG. 23 is an elevational view of the central body of FIG. 22.

FIG. 24 is a sectional view along the line 24-24 of FIG. 23.

FIG. 25 is a plan view of the central body of FIG. 22.

FIG. 26 is a perspective view of the central body of FIG. 1 withtrunnions being inserted into the central body and the yoke portionsremoved for clarity.

FIG. 27 is an elevational view of the central body of FIG. 26.

FIG. 28 is a sectional view along the line 28-28 of FIG. 27.

FIG. 29 is a sectional view along the line 29-29 of FIG. 27.

DETAILED DESCRIPTION

The present disclosure is generally directed to a universal joint thateliminates the spinning of bearing caps relative to yoke years andtrunnions and inhibits inadvertent spreading of opposing ears of a yokeaway from each other under increasing torsional loads to reduce wear andfailure of the joint. While the disclosed universal joint is primarilydiscussed herein for use in a vehicle drivetrain (e.g., drive shafts,axle shafts, etc.), it is to be understood that the joint can find usein numerous other contexts (e.g., power tools) which are encompassed inthe present disclosure.

With initial reference to FIGS. 1-4, a universal joint 100 fortransmitting rotary power (e.g., torque) from a first shaft 50 (e.g.,axle shaft) to an adjacent second shaft 54 (e.g., stub shaft) over avariety of angles between respective longitudinal axes 51, 55 of thefirst and second shafts 50, 54 is illustrated. Broadly, the universaljoint 100 includes a central body 104 having a housing 121 thatgenerally defines an internal cavity 122 along with first and secondyoke members or portions 108 ₁, 108 ₂ that are respectively rigidly(i.e., non-movably) attached to the first and second shafts 50, 54 inany appropriate manner and pivotally attached to the central body 104for pivotal movement about respective first and second reference axes116, 120 as discussed below.

With additional reference to FIGS. 22-25, the central body 104 includesa plurality of pairs of opposing apertures extending through the housing121 and leading into the internal cavity 122. For instance, the centralbody 104 may include first and second opposite apertures 124, 128through which the first reference axis 116 extends and third and fourthopposite apertures 132, 136 through which the second reference axis 120extends. In one arrangement, the central body 104 may further includefifth and sixth apertures 140, 144 through which a third reference axis150 extends. While the first, second, and third reference axes 116, 120,150 are all illustrated as perpendicular to each other, some embodimentsenvision that two or more of the first, second, and third reference axes116, 120, 150 may be disposed at non-perpendicular angles to each otherdepending upon the particular envisioned application of the universaljoint 100.

With reference to FIGS. 1-4, 10, and 11, the first yoke portion 108 ₁broadly includes a housing 154 ₁ defining first and second spaced armsor ears 158 ₁, 162 ₁ that are rigidly (i.e., non-movably) interconnectedby a bridge portion 166 ₁, where the bridge portion 166 ₁ may be rigidlyinterconnected to the first shaft 50. The first and second ears 158 ₁,162 ₁ may be spaced by an amount that is slightly greater than a maximumouter cross-dimension of the central body 104 along the first referenceaxis 116 to allow the central body 104 to be just received between thefirst and second ears 158 ₁, 162 ₁ taking into account any acceptabletolerances. As shown, the first ear 158 ₁ includes a first aperture 170₁ therethrough that is configured to be disposed over the first aperture124 of the central body 104 while the second ear 162 ₁ includes a secondaperture 174 ₁ therethrough that is configured to be disposed over thesecond aperture 128 of the central body 104 along the first referenceaxis 116.

Similarly, and with reference to FIGS. 1-4, 12, and 13, the second yokeportion 108 ₂ broadly includes a housing 154 ₂ defining first and secondspaced arms or ears 158 ₂, 162 ₂ that are rigidly (i.e., non-movably)interconnected by a bridge portion 166 ₂, where the bridge portion 166 ₂may be rigidly interconnected to the second shaft 54. The first andsecond ears 158 ₂, 162 ₂ may be spaced by an amount that is slightlygreater than a maximum outer cross-dimension of the central body 104along the second reference axis 120 to allow the central body 104 to bejust received between the first and second ears 158 ₂, 162 ₂ taking intoaccount any acceptable tolerances. As shown, the first ear 158 ₂includes a first aperture 170 ₂ therethrough that is configured to bedisposed over the third aperture 132 of the central body 104 while thesecond ear 162 ₂ includes a second aperture 174 ₂ therethrough that isconfigured to be disposed over the fourth aperture 136 of the centralbody 104 along the second reference axis 120.

To secure the first and second yoke portions 108 ₁, 108 ₂ to the centralbody 104 for respective pivotal movement about the first and secondreference axes 116, 120, a number of pivot pins or trunnions 178 may beinserted through the various ears of the first and second yoke portions108 ₁, 108 ₂ and into the internal cavity 122 of the central body 104along the first and second reference axes 116, 120. For instance, firstand second opposite trunnions 178 ₁, 178 ₂ may be respectively insertedthrough the first and second apertures 170 ₁, 174 ₁ of the first andsecond ears 158 ₁, 162 ₁ of the first yoke portion 108 ₁ and the firstand second apertures 124, 128 of the central body 104 and into theinternal cavity 122. See FIGS. 2 and 4. Similarly, third and fourthopposite trunnions 178 ₃, 178 ₄ may be respectively inserted through thefirst and second apertures 170 ₂, 174 ₂ of the first and second ears 158₂, 162 ₂ of the second yoke portion 108 ₂ and the third and fourthapertures 132, 136 of the central body 104 and into the internal cavity122.

With reference now to FIGS. 14-17, each trunnion 178 may include a head182 with a pin body 186 extending away from the head 182 to a free end190. The pin body 186 of each trunnion 178 is sized to pass through therespective ones of the apertures of the yoke portions and central body104 while the head 182 has a maximum outer cross dimension (e.g., outerdiameter) that is greater than a minimum internal cross dimension (e.g.,inner diameter) of at least a portion of the aperture of the respectiveyoke portion (so that the head 182 makes contact with the yoke portionand can apply a force against the yoke portion as discussed laterherein). In one embodiment, each of the first and second apertures 170₁/170 ₂, 174 ₁/174 ₂ of the first and second yoke portions 108 ₁, 108 ₂may include a depression 194 defined by a bottom surface 198 (e.g.,step) and a side surface 202 extending away from the bottom surface 198.See FIGS. 10-13. The bottom surface 198 may extend about a portion or anentirety of the respective aperture. The depression 194 defines a spacethat is configured to receive the head 182 of a trunnion 178 in a mannerthat prevents or inhibits rotation of the trunnion 178 about therespective one of the first and second reference axes 116, 120.

For instance, an outer perimeter 206 of the head 182 of each trunnion178 and the side surface 202 of the depression 194 of each of the firstand second apertures 170 ₁/170 ₂, 174 ₁/174 ₂ may have any appropriatenon-circular shape (e.g., tear drop as illustrated, square, hexagonal,etc.) to inhibit rotation of the trunnion 178 about the respective oneof the first and second reference axes 116, 120 when the head 182 isreceived in the depression 194. See FIGS. 2-4. Furthermore, a bottomsurface 210 of the head 182 is configured to contact the bottom surface198 of the depression 194 when the head 182 is seated or receivedtherein. In one arrangement, a thickness of the head 182 of eachtrunnion 178 (e.g., height of the outer perimeter 206) may beapproximately the same (e.g., taking account any appropriate tolerances)as a height of the side surface 202 of the depression 194. Furthermore,an overall curvature of the head 182 (or of the outer surface of thehead 182) may generally match that of the respective one of the yokeears. See FIGS. 6 and 16. In this regard, when the head 182 is fullyreceived in the depression 194, the head 182 may substantiallyseamlessly blend in with an outside surface (not labeled) of therespective one of the ears of the yoke portion which advantageouslyprotects the head 182 from environmental damage and the like.

To facilitate smooth and substantially frictionless rotation of each pinbody 186 within the respective one of the apertures 124, 128, 132, 136of the central body 104, any appropriate bearing structure 214 may bedisposed or otherwise formed within each of the apertures 124, 128, 132,136 to facilitate such rotation about the respective first or secondreference axis 116, 120. In one arrangement, each bearing structure 214may be in the form of a needle bearing as illustrated in FIGS. 1, 4, 7,and 9. However, the bearing structures 214 may take other forms such asa sleeve, liner, one-piece bushing, and/or the like. For instance, eachbearing structure 214 may be selected to have a maximum outercross-dimension (e.g., outer diameter) that is substantially the same as(e.g., slightly smaller than) a minimum internal cross dimension (e.g.,inner diameter) of the respective aperture 124, 128, 132, 136 and aminimum internal cross dimension (e.g., inner diameter) that issubstantially the same as (e.g., slightly greater than) a maximum outercross-dimension (e.g., outer diameter) of the pin body 186. Furthermore,an outer surface (not labeled) of the bearing structure 214 may berigidly fixed or otherwise non-movable relative to the central body 104.In one arrangement, any appropriate sealing ring or gasket 218 may bedisposed within each aperture 124, 128, 132, 136 between the bearingstructure 214 and the respective yoke ear 158, 162 to inhibit theintrusion of moisture and debris into the respective bearing structure214 as well as provide a sealed cavity for containing a lubricant (e.g.,grease, oil, etc.) to facilitate rotation of the trunnions 178 relativeto the bearing structures 214 and the locking assembly 222 (discussedfurther below). See FIGS. 1 and 4. In another arrangement, the sealingring 218 may form part of the respective yoke ear 158, 162 and contactthe respective trunnion 178 on an outside surface of the central body104.

To assemble the universal joint 100, the bearing structures 214 andgaskets 218 (if provided) may be appropriately inserted into and setwithin each of the apertures 124, 128, 132, 136 of the central body 204.In one arrangement, the bearing structures 214 and gaskets 218 may befixed within the apertures 124, 128, 132, 136 as part of themanufacturing of the central body 204 in any appropriate manner. In anyevent, the first and second apertures 170 ₁, 174 ₁ of the first yokeportion 108 ₁ may be disposed over and aligned with the first and secondapertures 124, 128 of the central body 104 and the first and secondapertures 170 ₂, 174 ₂ of the second yoke portion 108 ₂ may be disposedover and aligned with the third and fourth apertures 124, 128 of thecentral body 104. See FIGS. 1-4. Thereafter, the free end 190 of a firsttrunnion 178 ₁ may be inserted through the first aperture 170 ₁ of thefirst yoke portion 108 ₁ and the first aperture 124 of the central body104, the free end 190 of a second trunnion 178 ₂ may be inserted throughthe second aperture 174 ₁ of the first yoke portion 108 ₁ and the secondaperture 128 of the central body 104, the free end 190 of a thirdtrunnion 178 ₃ may be inserted through the first aperture 170 ₂ of thesecond yoke portion 108 ₂ and the third aperture 128 of the central body104, and the free end 190 of a fourth trunnion 178 ₄ may be insertedthrough the second aperture 174 ₂ of the second yoke portion 108 ₂ andthe fourth aperture 136 of the central body 104.

Each trunnion 178 may be inserted until its head 182 is seated in thedepression 194 of the respective one of the first and second apertures170 ₁/170 ₂, 174 ₁/174 ₂ as discussed previously (e.g., so that theouter periphery 206 of the head 182 generally matches the side wall 202of the depression 194 and so that the bottom surface 210 of the head 182is configured to contact the bottom surface 198 of the depression 194).See FIGS. 1, 4, 7, and 9. At this point, each trunnion 178 isnon-rotatable relative to its respective yoke portion 108 ₁, 108 ₂ suchthat the first yoke portion 108 ₁ and first and second trunnions 178 ₁,178 ₂ can all rotate as a single unit about the first reference axis116, and such that the second yoke portion 108 ₂ and third and fourthtrunnions 178 ₃, 178 ₄ can all rotate as a single unit about the secondreference axis 120.

Furthermore, the first and second trunnions 178 ₁, 178 ₂ can be securedagainst movement along the first reference axis 116 and the third andfourth trunnions 178 ₃, 178 ₄ can be secured against movement along thesecond reference axis 116 (while allowing for rotation of the first andsecond trunnions 178 ₁, 178 ₂ about the first reference axis 116relative to the central body 104 and rotation of the third and fourthtrunnions 178 ₃, 178 ₄ about the second reference axis 120 relative tothe central body 104) in any appropriate manner. Because the bottomsurface 210 of the head 182 is configured to contact the bottom surface198 of the depression 194 when seated in the depression, securing thetrunnions 178 against movement along the respective first or secondreference axis 116, 120 also necessarily secures the first and secondears 158 ₁, 162 ₁ of the first yoke portion 108 ₁ against outwardmovement or spreading along the first reference axis 116 and secures thefirst and second ears 158 ₂, 162 ₂ of the second yoke portion 108 ₂against outward movement or spreading along the second reference axis120. Preventing or inhibiting the tendency of yoke ears to spread duringhigh torque operation of the joint 100 advantageously increases theuseful life of the joint 100.

As an example, any appropriate locking assembly 222 may be inserted intothe internal cavity 122 of the central body 104 and into engagement withthe trunnions 178 to inhibit movement of the trunnions 178 along therespective first or second reference axis 116, 120. See FIGS. 1, 2, and29, where the first and second yoke portions 108 ₁, 108 ₂ have beenremoved in FIG. 29 for clarity. In one arrangement, the locking assembly222 may include a first locking member 226 that is configured forinsertion into the fifth aperture 140 of the central body 104 and intoengagement with the pin bodies 186 of the various trunnions 178 withinthe internal cavity 122 of the central body 104. For instance, the firstlocking member 226 may include a head 230 and a body 234 extending awayfrom the head 230, where the body 234 includes a plurality of engagementportions 238 that are configured to engage with corresponding engagementportions 188 of the pin bodies 186.

In one embodiment, the engagement portion 188 of each pin body 186 maybe in the form of an opening (e.g., slot, groove) extending partially orfully about an outer surface of the pin body 186 and each engagementportion 238 of the first locking member 226 may be in the form of aprojection (e.g., wall, protrusion, etc.) that is sized, shaped, and/orotherwise configured for receipt in the opening of the pin bodies 186 ina manner that inhibits axial movement of the trunnions 178 along therespective first or second reference axis 116, 120 (again, whilesimultaneously allowing for rotation of the trunnions 178 about therespective first or second reference axis 116, 120 relative to thecentral body 104 and locking assembly 222). For instance, it can be seenhow each respective set of engagement portions 188, 238 extends along areference plane (not labeled) that is perpendicular to the respectivefirst or second reference axis 116, 120 of the trunnion 178 to allow forrotation of the trunnions 178 while inhibiting axial movement 178). Inanother embodiment and while not shown, each engagement portion 188 ofeach pin body 186 may be in the form of a projection extending partiallyor fully about an outer surface of the pin body 186 and each engagementportion 238 of the first locking member 226 may be in the form of anopening that is sized, shaped, and/or otherwise configured for receiptof the projection of the pin bodies 186 in a manner that inhibits axialmovement of the trunnions 178 along the respective first or secondreference axis 116, 120.

The first locking member 226, central body 104 and trunnions 178 may beconfigured so that upon insertion of the first locking member 226 intothe fifth aperture 140 along the third reference axis 150, the head 230of the first locking member 226 in configured to contact the housing 122of the central body 104 substantially simultaneous with the engagementportions 238 of the first locking member 226 engaging with theengagement portions 188 of the trunnions 178. See FIGS. 4 and 28. In onearrangement, a sealing ring or gasket 242 may be positioned in the fifthaperture 140 to inhibit debris and fluids from intruding into theinternal cavity 122 of the central body 104 as well as provide a sealedinterior for lubricant. For instance, the fifth aperture 140 may includea depression therein (not labeled) including one or more steps (notlabeled) that are configured to receive one or more gaskets 242 forcompression thereof by the first locking member 226 (e.g., between alower surface of the head 230 and a step of the fifth aperture 140). SeeFIGS. 4 and 28.

In one embodiment, the locking assembly 222 may include a second lockingmember 246 that that is configured for insertion into the sixth aperture144 of the central body 104 and into engagement with the pin bodies 186of the various trunnions 178 within the internal cavity 122 of thecentral body 104. See FIGS. 1, 4, 7, 9, 18, and 28. The second lockingmember 246 may include a head 250 and a body 254 extending away from thehead 250, where the body 254 includes a plurality of engagement portions258 that are configured to engage with the engagement portions 188 ofthe pin bodies 186. For instance, the engagement portions 258 may besimilar to the engagement portions 238 of the first locking member 226.A sealing ring or gasket 262 may also be disposed within the sixthaperture 144 to inhibit the intrusion of debris or moisture into theinternal cavity 122 as well as provide a sealed interior for lubricant.

To secure the first and second locking members 226, 246 againstinadvertent removal from the central body 104 (and thus to ensure thatthe first and second locking members 226, 246 continue to engage withthe trunnions 178 to inhibit movement thereof along the respective firstand second reference axes 116, 120), the first and second lockingmembers 226, 246 may be selectively secured to each other in anyappropriate manner. In one arrangement, a fastener 266 may be insertedthrough an aperture 270 in the second locking member 246 along the thirdreference axis 150, between the free ends 190 of the various trunnions178, and then threaded into an aperture 228 in the first locking member226 to draw the heads 230, 250 of the first and second locking members226, 246 against the central body 104. See FIGS. 4 and 28. A sealingring or gasket 274 may be inserted into the aperture 270 in the secondlocking member before insertion of the fastener 266 to inhibit theintrusion of debris or moisture into the internal cavity 122 as well asprovide a sealed interior for lubricant. In one variation, a lockingring 276 may be disposed about a head (not labeled) of the fastener 266to inhibit unintentional removal thereof. See FIG. 2.

Any appropriate lubricant (e.g., oil, grease) may be disposed in theinternal cavity 122 of the central body 104 to facilitate rotation ofthe trunnions 178 relative to the bearing structures 214 and the lockingassembly 222. For instance, the housing 121 of the central body 104 mayinclude one or more channels 278 therethrough extending from an outsidesurface of the housing into the internal cavity 122 for injection orinsertion of such lubricant. Each channel 278 may be selectively closedby a removable plug 282 (e.g., cap) or the like.

FIGS. 5-7 illustrate the universal joint 100 with one of the first andsecond yoke portions 108 ₁, 108 ₂ being pivoted about its respectivefirst or second reference axis 116, 120 relative to the other of thefirst and second yoke portions 108 ₁, 108 ₂ so as to position thelongitudinal axes 51, 55 of the first and second shafts 50, 54 (theshafts 50, 54, not being shown in FIGS. 5-7 for clarity) at an angle σ.FIGS. 8-9 illustrate the angle σ being at a greater value than that inFIGS. 5-7 to allow for access to the fastener 266. In one arrangement,an inside portion of the bridge portion 166 ₂ of the second yoke portion108 ₂ may include a depression 286 therein to allow for a portion of thefirst yoke portion 108 ₂ to pass therein.

The various portions of the disclosed universal joint 100 may beconstructed of any appropriate materials and of any appropriatedimensions. It will be readily appreciated that many deviations may bemade from the specific embodiments disclosed in the specificationwithout departing from the spirit and scope of the invention. Forinstance, while the locking assembly 222 is illustrated as having thefirst and second locking members 226, 246 and the fastener 266, thelocking assembly 222 may in some embodiments utilize only a singlelocking member that is configured to grab around a substantial entiretyof each trunnion 178. In another example, the first and second lockingmembers 226, 246 may be configured to directly engage with each other.In one arrangement, the first and second locking members 226, 246 may beconfigured to engage with the central body 104 itself (e.g., via anon-circular through holes in the central body 104 to inhibit spinningof the first and second locking members 226, 246). As a further example,different locking members may be configured to grab different ones ofthe trunnions 178. In one arrangement, the pin body 186 of each trunnion178 may be configured to make direct contact with the inner wall of theaperture 174 of the respective yoke portion 108 (e.g., where no bearingstructure 214 would be included). In another arrangement, an innersurface of each of the first and second apertures 170 ₁/170 ₂, 174 ₁/174₂ may be tapered in a direction from outside the central body 104 to theinterior cavity 122 of the central body 104 to prevent the trunnions 178from passing therethrough and to inhibit spreading of respective pairsof yoke ears (e.g., instead of the depression 194 being provided).Various other arrangements are envisioned.

Certain features that are described in this specification in the contextof separate embodiments or arrangements can also be implemented incombination in a single embodiment or arrangement. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable subcombination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a subcombination or variation of a sub combination.

What is claimed is:
 1. A universal joint for connecting first and secondtorque transmitting shafts, the universal joint comprising: a centralbody having first and second opposite apertures through which a firstreference axis is defined and third and fourth opposite aperturesthrough which a second reference axis is defined; a first yoke portionthat is configured to be secured to a first torque transmitting shaft,wherein the first yoke portion includes first and second spaced oppositeears that are respectively disposed over the first and second oppositeapertures; first and second opposite trunnions that are respectivelyinserted through the first and second ears of the first yoke portion andthe first and second apertures of the central body to secure the firstyoke portion to the central body for pivoting about the first referenceaxis, wherein the first and second trunnions are non-rotatable relativeto the first yoke portion and each include a trunnion head with anon-circular outer perimeter, the trunnion head being seated within acorresponding depression formed on an outer surface of the first yokeportion, the corresponding depression having a non-circular outerperimeter sized and shaped to receive the trunnion head to inhibitrelative rotation between the first and second trunnions and the firstyoke portion; a second yoke portion that is configured to be secured toa second torque transmitting shaft, wherein the second yoke portionincludes first and second spaced opposite ears that are respectivelydisposed over the third and fourth opposite apertures; and third andfourth opposite trunnions that are respectively inserted through thefirst and second ears of the second yoke portion and the third andfourth apertures of the central body to secure the second yoke portionto the central body for pivoting about the second reference axis,wherein the third and fourth trunnions are non-rotatable relative to thesecond yoke portion.
 2. The universal joint of claim 1, wherein each ofthe third and fourth trunnions includes a trunnion head that has anon-circular outer perimeter, the trunnion head being seated within acorresponding depression with a non-circular outer perimeter formed onan outer surface of the second yoke portion, to inhibit relativerotation between the third and fourth trunnions and the second yokeportion.
 3. The universal joint of claim 2, wherein the trunnion head ofthe third trunnion and the trunnion head of the fourth trunnion eachhave a bottom surface in contact with a bottom surface of thecorresponding depression on the outer surface of the second yokeportion.
 4. The universal joint of claim 1, further including a lockingassembly disposed within the central body and secured to the first,second, third, and fourth trunnions to inhibit movement thereof alongthe first and second reference axes, respectively.
 5. The universaljoint of claim 4, wherein the first and second trunnions are rotatablerelative to the locking assembly about the first reference axis, whereinthe third and fourth trunnions are rotatable relative to the lockingassembly about the second reference axis.
 6. The universal joint ofclaim 4, wherein the central body further includes a fifth aperturethrough which a third reference axis extends, wherein the lockingassembly includes a first locking member that is inserted through thefifth aperture and into locking engagement with the first, second, thirdand fourth trunnions.
 7. The universal joint of claim 6, wherein each ofthe first, second, third and fourth trunnions includes a pin bodyextending from its respective head, wherein each pin body includes anopening that is configured to receive a portion of the first lockingmember to inhibit movement of the pin along the respective first orsecond reference axis.
 8. The universal joint of claim 7, wherein thecentral body further includes a sixth aperture through which the thirdreference axis extends, wherein the locking assembly includes a secondlocking member that is inserted through the sixth aperture and intolocking engagement with the first, second, third and fourth trunnions,and wherein the opening in each pin body is configured to receive aportion of the second locking member to inhibit movement of the pinalong the respective first or second reference axis.
 9. The universaljoint of claim 8, wherein the locking assembly further includes afastener extending through the first and second locking members alongthe third reference axis.
 10. The universal joint of claim 4, whereinthe trunnion head of the first trunnion and the trunnion head of thesecond trunnion each have a bottom surface in contact with a bottomsurface of the corresponding depression on the outer surface of thefirst yoke portion.
 11. The universal joint of claim 1, furtherincluding: first and second bearing assemblies respectively disposedwithin the first and second apertures of the central body to facilitaterotation of the first and second trunnions and the first yoke portionabout the first reference axis; and third and fourth bearing assembliesrespectively disposed within the third and fourth apertures of thecentral body to facilitate rotation of the third and fourth trunnionsand the second yoke portion about the second reference axis.
 12. Auniversal joint for connecting first and second torque transmittingshafts, the universal joint comprising: a central body having first andsecond opposite apertures through which a first reference axis isdefined and third and fourth opposite apertures through which a secondreference axis is defined; a first yoke portion that is configured to besecured to a first torque transmitting shaft, wherein the first yokeportion includes first and second spaced opposite ears that arerespectively disposed over the first and second opposite apertures;first and second opposite trunnions that are respectively insertedthrough the first and second ears of the first yoke portion and thefirst and second apertures of the central body to secure the first yokeportion to the central body for pivoting about the first reference axis;a second yoke portion that is configured to be secured to a secondtorque transmitting shaft, wherein the second yoke portion includesfirst and second spaced opposite ears that are respectively disposedover the third and fourth opposite apertures; third and fourth oppositetrunnions that are respectively inserted through the first and secondears of the second yoke portion and the third and fourth apertures ofthe central body to secure the second yoke portion to the central bodyfor pivoting about the second reference axis; and a locking assemblydisposed within the central body and secured to the first, second, thirdand fourth trunnions to inhibit movement thereof along the first andsecond reference axes, respectively, wherein a head of each of the firstand second trunnions includes a surface that contacts a lower surface ofa corresponding depression formed on an outer surface of the first yokeportion to inhibit movement of the first and second ears of the firstyoke in first and second opposite direction along the first referenceaxis, and wherein a head of each of the third and fourth trunnionsincludes a surface that contacts a lower surface of a correspondingdepression formed on an outer surface of the second yoke portion toinhibit movement of the first and second ears of the second yoke portionin first and second opposite direction along the second reference axis.13. The universal joint of claim 12, wherein the first and secondtrunnions are rotatable relative to the locking assembly about the firstreference axis, wherein the third and fourth trunnions are rotatablerelative to the locking assembly about the second reference axis. 14.The universal joint of claim 12, wherein the central body furtherincludes a fifth aperture through which a third reference axis extends,wherein the locking assembly includes a first locking member that isinserted through the fifth aperture and into locking engagement with thefirst, second, third and fourth trunnions.
 15. The universal joint ofclaim 14, wherein each of the first, second, third and fourth trunnionsincludes a pin body extending from its respective head, wherein each pinbody includes an opening that is configured to receive a portion of thefirst locking member to inhibit movement of the pin along the respectivefirst or second reference axis.
 16. A method of assembling a universaljoint, comprising: positioning first and second spaced ears of a firstyoke portion over respective first and second spaced apertures of acentral body; inserting a first trunnion through the first ear of thefirst yoke portion and the first aperture of the central body along afirst reference axis until a non-circular perimeter of a head of thefirst trunnion is seated within a non circular corresponding depressionwith a non-circular outer perimeter formed on an outer surface of thefirst ear of the first yoke portion to inhibit relative rotation betweenthe first trunnion and the first yoke portion; inserting a secondtrunnion through the second ear of the first yoke portion and the secondaperture of the central body along the first reference axis until anon-circular perimeter of a head of the second trunnion is seated withina corresponding depression with a non-circular outer perimeter formed onan outer surface of the second ear of the first yoke portion to inhibitrelative rotation between the second trunnion and the first yokeportion; positioning first and second spaced ears of a second yokeportion over respective third and fourth spaced apertures of the centralbody; inserting a third trunnion through the first ear of the secondyoke portion and the third aperture of the central body along a secondreference axis until a non-circular perimeter of a trunnion head of thethird trunnion is seated within a corresponding depression with anon-circular outer perimeter formed on an outer surface of the first earof the second yoke portion to inhibit relative rotation between thethird trunnion and the second yoke portion, wherein the first and secondreference axes are perpendicular; and inserting a fourth trunnionthrough the second ear of the second yoke portion and the fourthaperture of the central body along the second reference axis until anon-circular perimeter of a trunnion head of the fourth trunnion isseated within corresponding depression with a non-circular outerperimeter formed on an outer surface of the second ear of the secondyoke portion to inhibit relative rotation between the fourth trunnionand the second yoke portion; and inserting a locking apparatus intocentral body and into contact with the first and second trunnions toinhibit movement of the first and second trunnions along the firstreference axis while allowing for rotation of the first trunnion, secondtrunnion, and first yoke portion about the first reference axis relativeto the locking member.
 17. The method claim 16, wherein the insertingthe locking apparatus includes inserting the locking apparatus into thecentral body and into contact with the third and fourth trunnions toinhibit movement of the third and fourth trunnions along the secondreference axis while allowing for rotation of the third trunnion, fourthtrunnion, and second yoke portion about the second reference axisrelative to the locking member.
 18. The method of claim 17, wherein theinserting the locking apparatus includes: inserting a first lockingmember through a fifth aperture in the central body along a thirdreference axis and into contact with the first, second, third and fourthtrunnions; and inserting a second locking member through a sixthaperture in the central body along the third reference axis and intocontact with the first, second, third and fourth trunnions.